"I don't object to foreigners expressing their opinion," Harper told the CBC. "But I don't want them to be able to hijack the process so that we don't make a decision that's timely or in the interests of Canadians."

Harper was referring to President Obama's decision to delay approval of TransCanada's pipeline. He added that the news "was a wakeup call about the degree to which Canada is 'held hostage' to U.S. decisions."

Just a bit of a refresher: The Keystone pipeline was supposed to run through the delicate Sandhills of Nebraska. Environmentalists made the issue a key rallying point, so Obama tried to delay his decision until after the 2012 elections. After the president announced his delay, TransCanada announced it would reroute the pipeline. And later, as part of the payroll tax cut negotiations, President Obama said he would make a decision on the pipeline by Feb. 21.

Harper also addressed the fact that foreign money is going to Canadian environmental groups to fight the pipeline.

"It's one thing in terms of whether Canadians, you know, want jobs, to what degree Canadians want environmental protection," said Harper. "These are all valid questions, but just because certain people in the United States would like to see Canada be one giant national park for the northern half of North America, I don't think that's part of what our review process is all about."

Harper added that the pipeline is crucial from an "energy security standpoint," especially now that Iran is threatening to block the Strait of Hormuz.

"I think that just illustrates how critical it is that supply for the United States be North American," he said, according to Reuters.